ALAMEDA, Calif. — Amari Cooper's upward career trajectory took a major detour last season when a combination of drops, injuries and overall poor play plagued him all season.

After topping 1,000 yards receiving in each of his first two seasons in the NFL for Oakland, Cooper didn't even reach 700 yards last season in a fall that was emblematic of the Raiders descent from 12 wins in 2016 to just six a year ago.

That all contributed to the move to bring Jon Gruden back for a second stint as coach and Gruden made it clear earlier in the offseason that fixing Cooper would be a priority and that he expected him to be a focal point of the offense.

"It was cool. Obviously as a receiver, you want to go out there and make plays for your team and win," Cooper said Tuesday. "So for him to say that, it really meant a lot to me. I'm just ready to come out here and work and prove that I deserve to have those opportunities."

Cooper was on a star track after being drafted fourth overall by the Raiders in 2015. He had 72 catches for 1,070 yards as a rookie and then 83 receptions for 1,153 yards in year two, becoming the third player to start his career with back-to-back seasons with at least 70 catches and 1,000 yards receiving after Odell Beckham Jr. and Marques Colston.

But he took a major step backward last season when he had just 48 catches for 680 yards with nearly one-third of that production (210 yards) coming in a Thursday night win over Kansas City. Cooper had more than 70 yards receiving just one other time all season, when he gained 87 of his 115 yards on a single catch in the season finale.

Cooper caught just 50 percent of his 96 targets last season for the third-worst mark in the NFL last season, according to SportRadar.

"I wouldn't say it was great," Cooper said. "Definitely some things I need to work on coming into this year and some things that I have been working on so that I can be better on for this season."

Holding onto the ball will be a big key. He dropped three passes in the opener and five in the first four weeks, according to SportRadar, to get his season off on the wrong track. He reduced those as the season went on, but was unable to perform consistently as the Raiders offense struggled as a whole with Derek Carr at quarterback.

But drops have been a recurring problem for Cooper in his career with his 30 dropped passes since entering the league in 2015 ranking worst in the NFL. The Raiders have 135 as a team in that span, also ranking last in the league and a priority for Gruden to fix.

"Sometimes the quarterback throws the ball in there early. Maybe he didn't take the proper drop. Sometimes the receiver might lack concentration. There's a lot of reasons. You have to catch the football," Gruden said.

"We have to catch the ball better. We have to improve. Our receivers have to rise up, play better than they've ever played. We've made changes there in this core and they have to obviously take the torch and run with it."

Cooper is part of an offense that should maximize his talent this year. In 11 years as a coach, Gruden had a 1,000-yard receiver every season, including two in 2001. The Raiders also bolstered their receiving group by signing Jordy Nelson to replace the departed Michael Crabtree and adding a deep threat in Martavis Bryant, whose game-breaking speed should create more opportunities underneath.

Having two talented receivers by his side also should allow Cooper more opportunities to play from the slot, where his deft footwork and route running should make him a difficult matchup.

"We have a whole lot of plays even right now this early," Cooper said. "We have something for everything. Every defensive look, we can audible to something to get in the right play for any defense."

NOTES: The Raiders traded a conditional seventh-round pick to the New York Jets for quarterback Christian Hackenberg, a second-round pick in 2016 who has never taken a snap in the NFL. ... Edge rusher Khalil Mack remains out of the voluntary offseason program while seeking a long-term contract. ... S Obi Melifonwu, a second-round pick in 2017, remains sidelined by a hip injury and Gruden said he's not close to returning. "I haven't seen much of Obi except in the training room," Gruden said.